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sulfate is insufficient to shift the anion component to a sulfate type with concentrations of bicarbonate and sulfate being approximately equal at TR-D. The nitrite/nitrate anion component (Figure 9) closely follows the same trend as sulfate, but to a much lesser extent. The most probable source of readily available nitrite/nitrate at the mine is the mulch used during the re vegetation process. All of the detectable trace elements: iron (Figure 6), aluminum (Figure 7), manganese (Figure 7), phosphorus (Figure 8) and zinc (Figure 8) show consistently low values since the fall of 1981, except during the rapid snow melt which occurred during 1989. At that time, a dramatic increase in each of these parameters occurred upstream of TA-A with significant dilution being observed at each successive monitoring point along the mine area. The dilution was caused by the low concentrations of these elements in water exiting from the mine. This same diluting effect is also expressed in the TSS concentrations as previously mentioned. Dissolved iron and zinc also show the • rising and falling trend expressed in the TDS observations with peak concentrations occurring prior to the spring runoff and dilution with the higher flows. All the values observed from these elements, except May, 1984, are consistent with the baseline values. Other trace elements: arsenic (Figure 9), selenium (Figure 9), and mercury (Figure 10) have remained below detectable limits with a few exceptions occurring prior to 1984. These values suggest potential contributions from these elements to Trout Creek water quality from mining activities are not evident. The general characteristics: pH (Figure 11), electrical conductivity (Figure 11), temperature (Figure 12) and dissolved oxygen (Figure 12) exhibit the same trends as found during the baseline studies. Trout Creek remained alkaline throughout the year with slight variations in pH occurring seasonally. Electrical conductivity shows the same trend as TDS, as expected. Temperature follows the seasonal trend established during baseline and dissolved oxygen remains near saturation.